SURFACE-TENSION OF WATER BY THE METHOD OF JET VIBRATION 



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gasburner heating the bath. In this way the temperature of the water could be 

 kept constant at 0'01 C. as long as wanted. 



The arrangement for keeping the pressure constant is shown in fig. 1. The water 

 coming from the heating apparatus was led into a glass-bottle A, in which a constant 

 water-level was maintained with help of an overflow B. From A the water was led 

 down to the pressure-reservoir, consisting of two 5-litre glass-bottles C and D. 



Fig. 1. 



Inside C was placed an overflow E. G and D were connected by a wide bent-glass- 

 tube F. H and K were two outlets through which the bottles could be emptied. 

 From D the water was led down through a long glass-tube L to the jet-tube M. 

 The whole arrangement was situated in a cellar, and the pressure-reservoirs as well 

 as the jet-tube were supported by stone foundations. At the beginning of each 

 experiment all the reservoirs and tubes were carefully cleaned and rinsed, whereupon 

 the waterflow was adjusted so that a constant not particularly rapid flow ran through 

 both the overflows. 



With the arrangement mentioned, the water- surface in the bottle D was very 

 steady and quite independent of the variations of the pressure in the supply pipe. 



The temperature of the water was very near 12 C. in all experiments. 



In order to calculate the surface-tension of a liquid, the following quantities had to 

 be known : (1) the density, p ; (2) the discharge per second. V; (3) the velocity of 



